Abstract Stress and anxiety create significant barriers to student well-being and academic success, particularly in rural communities where children and families have less access to mental health resources than their urban peers. Mindfulness-based Interventions (MBIs) can improve symptoms of stress and anxiety and are increasingly being implemented in school settings. Despite their growing popularity, school-based MBIs lack a trauma-sensitive approach to delivery and have yet to undergo rigorous empirical study. Further, most school- based MBIs target elementary and high school students even though the average onset for mental health diagnoses is during middle school. As anxiety symptoms are at an all-time high among students in the U.S., state legislators and school staff are calling for effective mental health programs to be integrated into our educational system. The proposed intervention, Trauma-Informed Mental Health in Education (TimeIn), is a universal mindfulness-based mental health curriculum for middle school children. TimeIn aims to reduce stress, anxiety and depression while improving social skills, self-efficacy and student behavior through enhanced executive functioning and emotion regulation. TimeIn will draw upon best practices from psychology to be trauma- sensitive and from applied research in education settings to be culturally appropriate and easily integrated into existing middle school curricula. Given the role of teachers as change agents for children, the intervention will include support for middle-school teachers during delivery in the form of online professional learning communities (PLCs). Online PLCs are a novel adaptation of an evidence-based, empirically validated face-to- face approach for building teacher knowledge, capacity, and self-efficacy. The TimeIn curriculum and online support will increase accessibility to mental health resources for all students, and particularly for those in rural schools. During Phase I, the project team will use human-centered design to transform three modules of an in- person iteration of TimeIn into a low-fidelity prototype for the web-based version of the TimeIn curriculum. They will then assess its design, content validity and feasibility and design the PLC collaboration features for teachers. Once complete, the team will iteratively develop and assess a high-fidelity prototype with a total of six modules. Phase II will focus on developing the remaining five modules of the TimeIn curriculum and evaluating the efficacy, feasibility and user satisfaction in a randomized control trial. The proposed work will result in a validated, 11 module online course, with PLC collaboration features for teachers, that helps middle school students learn and practice mindfulness to improve psychological and cognitive function.